Medial Branch Block

BACKGROUND

The facet joints are small joints between the vertebra which make up the spine.  These joints can be injured and may become a source of persistent spinal pain.  

 

There are no reliable physical signs or X-ray features which can prove that a facet joint is painful.  The only way to determine whether these joints hurt is to anaesthetise it temporarily.  

 

PROCEDURE

If you are pregnant or on blood thinners, you should inform us before the procedure.  These tests involve exposure to X-rays.  The X-ray dose is within the recommended safe limits for adults, but may be potentially hazardous for a developing foetus.

 

It is vital that your usual pain is present on the day of the procedure - you must have enough pain to determine whether or not it stops following the block.  

You will probably need to stop your usual pain medications for up to 2 days before.

 

Please arrange for a friend or relative to drive you home after your injection appointment, as you may be a little unsteady or feel slightly numb or weak to drive. You can eat and drink as normal before and after the procedure. 

 

During the procedure, you will be made comfortable and lying face down. You will be completely awake and able to listen and speak during the procedure.  If at any time you are concerned or want to stop the procedure you can say so.  However, this is unlikely to be necessary.

 

Before the procedure starts, antiseptic is applied to the skin surrounding your sacroiliac joint and a sterile drape is placed over the area.  Local anaesthetic is then used to numb the area which can feel uncomfortable in the short term. The needle is then advanced into the target point and a small amount of local anaesthetic and corticosteroid is then injected. 

The whole procedure usually takes less than 30 minutes.  

 

After the procedure, you will be required to remain at the radiology facility for about 30minutes, so the result of the block can be assessed.  

At follow-up assessments you will be asked to grade your pain level and to test if any of your Activities of Daily Living (ADLs) have been restored.  Within a short time after the block you should know if it has relieved your pain; the difference is usually “black or white”

If your pain is not relieved, don’t be afraid to say so. 

If only part of your pain is relieved, try to explain which part has been relieved and which part has not.  

You will be contacted by telephone to assess the longer-term results of the block.

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RISKS

Sometimes, the needles can cause some bruising in the low back muscles which may produce muscle soreness or stiffness for up to 2-3 days.  

Sometimes when patients obtain relief, they experience a “rebound” effect when their pain returns, that is, it feels worse at first then settles back down to the accustomed level. It is recommended that you do not undertake any extraordinary activities while the block is in effect. 

The other potential risks associated with these blocks are extremely unlikely, but include allergy to the antiseptic or local anaesthetic, or the introduction of infection.  If you have any redness, swelling or increasing pain please call us immediately.

 

TREATMENT

If it is determined that you have a painful facet joint, treatment is a Radiofrequency Neurotomy of the nerve. This will deactivate the nerve by using thermal ablation. This should abolish your pain for a period lasting from ten months to indefinitely.